The first step, of course, is to rip the head off.

At least, from what paleontologists from Montana's Museum of the Rockies gather, that's how Tyrannosaurus Rex did it.

From Nature:

As [Denver Fowler] and his colleagues examined the various types of bite mark on the skulls, they were intrigued by the extensive puncture and pull marks on the neck frills on some of the specimens. At first, this seemed to make no sense. “The frill would have been mostly bone and keratin,” says Fowler. “Not much to eat there.” The pulling action and the presence of deep parallel grooves led the team to realise that these marks were probably not indicative of actual eating, but repositioning of the prey. The scientists suggest that the frills were in the way of Tyrannosaurus as it was trying to get at the nutrient-rich neck muscles.

“It's gruesome, but the easiest way to do this was to pull the head off,” explains Fowler with a grin. The researchers found further evidence to support this idea when they examined the Triceratops occipital condyles — the ball-socket head—neck joint — and found tooth marks there too. Such marks could only have been made if the animal had been decapitated.

Awesome. For the rest of that article, check out Nature.com.

And now, people in rubber dinosaur suits fighting: